In this study we want to investigate if a prolonged exercise training program can lower the intrahepatic lipid content and can improve the metabolism of the liver in type 2 diabetic patients and patients with non-alcoholic fatty liver disease, and to examine if this leads to improvements in metabolic risk markers. To this end, we will include investigation of the effect of exercise on adipose tissue (inflammatory markers and adipocyte size) and skeletal muscle (ex vivo lipid metabolism) to incorporate the effect of exercise on liver, muscle and adipose tissue and to clarify the crosstalk between these tissues in the pathophysiology of type 2 diabetes.